Network mask in IPv6 for DNS server is rejected by Netplan ("Error in network definition: malformed address")
On a recent server install the netplan apply
command fails with the following error message:
/etc/netplan/0-base.yaml:18:9: Error in network definition: malformed address '2001:41d0:3:163::1/128', must be X.X.X.X or X:X:X:X:X:X:X:X
- 127.0.0.1
Here is the (redacted) content of generated /etc/netplan/0-base.yaml
:
---
network:
version: 2
renderer: networkd
ethernets:
eno1:
addresses:
- 2001:db8:1234:5678:9::abcd:ef/64
- 213.186.33.6/24
dhcp4: false
dhcp6: false
gateway4: 213.186.33.254
gateway6: 2001:db8:1234:56ff:ff:ff:ff:ff
nameservers:
search:
- ovh.net
addresses:
- 127.0.0.1
- 213.186.33.99
- 2001:41d0:3:163::1/128
routes:
- to: 2001:db8:1234:56ff:ff:ff:ff:ff/128
scope: link
...
The 2001:41d0:3:163::1/128
IPv6 address in network.ethernets.eno1.nameservers.addresses
has a network mask, which is not accepted by Netplan.
Removing the /128
part fixes the problem.